Oilpan: Rename weak callback related methods

Source/platform/heap/ThreadState.h

Index: Source/platform/heap/ThreadState.h
diff --git a/Source/platform/heap/ThreadState.h b/Source/platform/heap/ThreadState.h
index 6c54dfed56576c33f5dcf76cf1241383f646699a..68b396c1e8419423050ae932eeb36d4e37be0f7e 100644
--- a/Source/platform/heap/ThreadState.h
+++ b/Source/platform/heap/ThreadState.h
@@ -498,8 +498,8 @@ public:
     void reportMarkSweepStats(const char* statsName, const ClassAgeCountsMap&) const;
 #endif
 
-    void pushWeakPointerCallback(void*, WeakPointerCallback);
-    bool popAndInvokeWeakPointerCallback(Visitor*);
+    void pushThreadLocalWeakCallback(void*, WeakPointerCallback);
+    bool popAndInvokeThreadLocalWeakCallback(Visitor*);
 
     size_t objectPayloadSizeForTesting();
     void prepareHeapForTermination();
@@ -697,7 +697,7 @@ private:
     bool m_shouldFlushHeapDoesNotContainCache;
     GCState m_gcState;
 
-    CallbackStack* m_weakCallbackStack;
+    CallbackStack* m_threadLocalWeakCallbackStack;
     HashMap<void*, bool (*)(void*, Visitor&)> m_preFinalizers;
 
     v8::Isolate* m_isolate;